Br. Babu et al., EFFECT OF AN ABUNDANT HUMAN SKIN MELANOSOMAL 66 KDA PROTEIN (MP-66) ON MURINE TYROSINASE - ITS PHYSIOLOGICAL IMPLICATIONS ON MELANOGENESIS, Journal of Biosciences, 23(2), 1998, pp. 125-129
A single polypeptide protein (MP 66) of molecular weight 66kDa purifie
d to homogeneity from melanosomes of normal skin epidermal melanocytes
, was partially characterized. The isoelectric point of MP 66 is in th
range of 7•3 to 7•6. This protein, which was shown to inhib
it partially purified human skin tyrosinase activity at pH 6•8,al
so inhibits murine tyrosinase of pH 6•8. However, at pH 5•0,
it stimulates murine tyrosinase activity. The physiological implicati
ons of these results are discussed.